A variety of polysulfones and polyesters are commercially available for use in different applications such as adhesives, moldings, membranes and composite matrices. The uncrosslinked forms of these materials are sensitive to certain solvents especially when they are under load. Polysulfones are not available in crosslinked forms whereas a variety of thermosetting polyesters are available. Sulfone/ester polymers have been reported but not those containing pendent ethynyl groups. Ether-ketone-sulfone polymers containing pendent ethynyl groups have been reported (C. Samyn and C. S. Marvel, J. Polym, Sci. Polym. Chem. Ed. 13 (1975) 1095; and in U.S. Pat. No. 3,935,167 (Marvel et al). However, the ethynyl group was introduced into the polymer through a synthetic route (Vilsmeyer reaction-conversion of an acetyl group to a chlorocinnamalaldehyde and subsequent cleavage with base to the acetylene) which does not provide a quantitative yield. This polymer containing pendent ethynyl groups was subsequently crosslinked with a catalyst (PdCl.sub.2) or through reaction with terephthalonitrile N,N'-oxide.
Commercially available high performance thermoplastics such as the polyarylene ether sulfones, sold under the tradename UDEL.RTM. (polysulfone) by Union Carbide Corporation and Victrex.RTM. (polyethersulfone) by Imperial Chemical Industries, are recognized as tough materials. However, these materials are sensitive to certain solvents, especially under stress, and therefore are unacceptable for use in composite structures on commercial and military aircraft where resistance to long term exposure to fluids and paint strippers and temperature cycling is an essential requirement.
The present invention is directed to an improved class of high performance polymers, novel monomers and oligomers, and the process for preparing same that incorporate all the advantageous features of the prior art while minimizing or eliminating the disadvantages featured thereof.
Accordingly, it is an object of the present invention to provide a novel class of polymers having improved solvent resistance, toughness, thermoformability and mechanical performance.
Another object of the present invention is to provide chemically modified thermoplastics that are useful in making tough adhesives, coatings, membranes and composite matrices, all having improved solvent resistance.
Another object of the present invention is a novel class of sulfone-ester polymers containing pendent ethynyl groups.
A further object of the present invention is a process for preparing sulfone-ester polymers.
Another object of the present invention is the new composition of matter 5-(4-ethynylphenoxy)isophthaloyl chloride useful in the synthesis of the sulfone-ester polymers.
An additional object of the present invention is a process of making 5-(4-ethynylphenoxy)isophthaloyl chloride.
A further object of the present invention is a novel class of sulfone-ester polymers that are thermally curable without the use of a catalyst.